Filtering apparatus



Nov. 3, 1942. LL Y 2,300,789

FILTERING APPARATUS Filed July 6, 1939 I 3 Sheets-Sheet l 3nn'entorBLAINE KELLEY attorney Nov. 3, 1942. 4 BAKELLEY 2,300,189

FILTERI NG APPARATUS Filed July 6, 1939 3 Sheets-Sheet 2 A I Invent'or:E KELLg L I L I l Ii 1 I 1 7 2 1',"

. Nov. 3, 1942. v L EY 2,300,789

FILTERING APPARATUS Filed July 6, 1939 3 Sheets-Sheet 3 ,3nventor:

BLAINE KELLEY Patented Nov.- 3, 1942 UNITED 21 Claims.

This invention relates to a cleansing apparatus for garments and thelike and more especially to i an apparatus of this type having meansassociated therewith for continuously purifying the cleansing fluid.

It is an object of this invention to provide the combination of acleansing vat in which garments are cleaned and a fluid purificationtank with a filtering device therein and means for circulating the fluidfrom the vats through the filter and again back into the vat while thevat is in operation.

It is another object of this invention to provide a circulating systemof the class described having means for reversing the flow of thecleansing fluid through the filtering means when it is desired tocleanse the filter.

It is a still further object of this invention to provide a purificationtank for dry cleaning apparatus having upper and lower compartmentsscription proceeds when taken in connection with the accompanyingdrawings, in which- Figure 1 is an elevation showing the combination ofa washing vat, purification tanks, pump, and interconnecting pipestherebetween;

Figure 2 is a vertical sectional view through the purification tankshown in the left hand portion of Figure 1; 59

Figure 3 is a vertical sectional view through the purification tanktaken along the line 3-3 in Figure 1;

Figure 4 is a sectional plan view taken along the line 4-4 in Figures 1and 2; r

Figure 5 is a sectional plan view taken along the line 55 in Figures 1and 2;

Figure 6 is an isometric view showing the structure of the concentricfilter grids which are dis- 5O limit the stroke of the lever 4L posed onthe interior of the filtering tank;

Figure 7 is a sectional plan view taken along the line i! in Figure 6;

Figure 8 is a vertical sectional view taken along the line 88 in Figure6;

I'l'" Figure 9 is a vertical sectional view taken along ments are placedfor cleaning purposes. Leadto The partition between the compartment ingfrom the lower side of this vat is a pipe II which extends to the intakeside of pump [2; Valve M and drain l5 are disposed intermediate the endsof the pipe II. The pump 12 has a pulley 16 upon which a belt I! ismounted and this belt is also mounted upon-a motor pulley l8 of motor20. The'outlet side of the pump I 2 has a pipe 24 leading therefrom andfrom the pipe 24 another pipe 25 leads into the lower portion ofcompartment 26 of purification tank 21. Pipe'25 has a suitable handvalve 28 disposed therein and also a check valve 29 to prevent thesolution from flowing backwardly in the pipe, that is, flowing from thetank toward the pump.

The lower portion of the tank 27 has a sediment compartment 3|, saidcompartment 31 being separated from the compartment 26 thereabove bymeans of a suitable bottom or partition 32. By observing Figure 5, itwill be noted that the bottom 32 has a plurality of radially disposedslots 33 therein through which the sediment which accumulates upon thebottom is allowed to pass p t The bottom 32 has rotatably mountedtherein a vertically disposed pipe 34 which has extending radiallytherefrom a pluralityofscraping and closure members 35. These scrapingmembers rest upon. the top of the partition 32 and normally close theslots 33 but are adapted to scrape the surface between the radial slots33 when the pipe 34 is rotated. It isseen that as these arms are rotatedthat the sediment which has accumulated upon the bottom will be forcedinto the openings 33 from which it will settle into the sedimentcompartment 3! therebelow.

The lower end of the pipe 3 1 has a horizontally extending shaft 38secured therein, the free end of which is adapted to loosely fit in theupper end of forked member 39, said forked memberhaving its lower endfixedly secured upon the inside end of a horizontally disposed shaftit]. The shaft 6! is rotatably mountedin the sidewall of the tank 27 andhas its other end projecting on the exterior thereof. On the projectingend of the shaft 59 a suitable hand lever M is fixedlysecured for theoperation of the shaft when it is' desired to oscillate the scrapingmembers back and forth. Stop members 43 and 44 are provided to The upperend of the pipe 34 has a cylindrical drum 41 mounted thereon. This drumis mounted in the central portion of the tank 2'! and serves to assistin proper circulation of the cleansing fluid in the upp r compartment.In other words, this cylinder is a simple obstruction which prevents thedefinite upwardly whirling flow from becoming a wild, turbulent flow.Where the whirling flow is too great, a vortex is formed in the centerof the tank, thus drawing thersolid substance to this point. The meansfor creatin this whirling flow will be later described.

Concentrically disposed around the cylindrical member 4? are filtergrids 89 and 58. The lower ends of these grids are supported bylaterally and inwardly projecting members 55 and 56 extending from theinterior sidewalls of the upper compartment. Extending upwardly from thelaterally projecting members 55 and 58 are rods 51 and 58, said rodsbeing disposed between the two concentric grids and having lugs 59 and60' respectively on the upper ends thereof which lugs are held againstthe upper portion of the grids 48 and 50 to secure the same in fixedposition within the compartment.

The upper end of the tank 2'! is normally closed by a cap 82. This caphas a plurality of radial slots 83 disposed therein in which verticallydisposed rods 64 are adapted to fit. The lower ends of the rods 64 arepivoted as at 65 to the exterior of the upper portion of the tank andthe upper end of each rod has threadably secured thereon a hand wheel 60which is manipulated to clamp the cap firmly over the upper end of thetank. The central portion of the cap 82 has a threaded bore 61 therein.A rod 68 is threadably secured in this bore, the upper end of this rodhaving a hand wheel 88 fixedly secured thereon. The portion of rod 68directly below the hand wheel, is rotatably mounted ina horizontalcantilevered member I and this member is supported by a verticallydisposed post II, the lower end of which is rotatably mounted in bearing12 extending laterally from the periphery of tank 21. When it is desiredto remove the cover 62, it is necessary to first loosen the hand wheels66 and then rotate the hand wheels and their associated rods 64 aboutthe pivot points 65 until they become disengaged from the slots 83 inthe cap. Then the hand wheel 69 is turned to cause the cap 62 to beraised from the top of the tank, after which the supporting post II isrotated so that the lid or cover will be removed from above the tank.

The screens 48 and 50 have outlets 82 and 83 leading therefrom (seeFigures 2, 3 and 6), which are adapted to seat upon the upper ends ofpipes 85 and 88, respectively, said pipes extending through the sidewallof the tank. The pipes 85 into the vat I8. Of course it will benecessary when the fluid is flowing in this direction for the valves I4,28, 88, 9| and 95 to be opened, and for the valves I5 to S8 to beclosed.

Figures 6 to 9 inclusive show an enlarged detail view of a portion ofthe filter grid 48. It is here noted that the filter grid 89 has upperand lower rims I80 which are U-shaped in cross section. Within thisU-shaped rim the upper and lower edges of a coarse mesh screen IN isadapted to fit. This coarse screen is interposed between two fine meshscreens I83 and I84, the fine mesh screen I03 being disposed on theinterior and the screen I04 being disposed on the exterior of the coarsemesh screen. Extending from the top to the bottom of the filter is apipe I85, said pipe being an upward extension of the outlet 82therebelow. This pipe has vertical U-shaped trenches I88 extending fromopposed sides there on in which the edges of the screen members IOI andI83 and I04 are adapted to fit. Suitable slots I8! are cut in the pipeI85 at such a position that they will provide a communication betweenthe interior of the pipe and. the U-shaped trenches I88. Since in normaloperation the cleansing fiuid is forced from the exterior to theinterior of the filter grids, the fluid will find an outlet by way ofthe slots I81 to the interior of the pipe I85 from whence it will escapeto the exterior by Way of outlet 82 and pipes 85 and pipe 81. Anyforeign matter which happens to be in the cleansing fiuid will beretained by the fine mesh screens I83 and I80, thereby allowing thepurified fluid to pass again into the tank or vat I0. Thefilter grid isidentical in construction except that it is larger in diameter, hencelike reference characters will be applied to corresponding parts andanother description will not be made. The pipe I05 has a division I05aforming semicircular passageways I88 and IE9 on each side thereof, whichextends the entire length of the pipe. Whenever foreign matteraccumulates within the interior of the grid construction it is necessaryto remove the grid from the tank and then direct a fluid under pressureinto one side of the pipe as at I08 from whence it will pass outwardlythrough slots #0? and between the fine mesh cylindrical screens I03 andI84 and back and 86 have connected to the exterior ends thereof pipes 81and 88 and these pipes have their other ends connected to a verticallydisposed pipe 89. The pipes 81 and 88 also have hand valves 98 and 9!,respectively therein which are used when it is desired to direct thesolution through one screen only or to control the amount of fluidpassing through the screens. The upper end of the pipe 88 has a checkvalve 93 therein and connected to the other side of the check valve isanother pipe 84 with a valve 85 therein which leads back into thewashing vat I8.

It will be noted (Figure 1) that the pipe 24 has a hand valve 98 thereinwhich is normally closed when the circulating system is in operation andthe washing vat is washing or cleaning garments and the like. At thistime the solution in into passageway I03. This gives a washing action tothe interior of the grid and is possible only because the grid iscylindrical in shape.

After the machine has been in operation for W some time, the screens I03and I84 become coated with foreign substances and therefore, it isnecessary to remove this foreign matter. In order to effectively do so,it has been found practical to reverse the direction of flow of theliquid in the filter grids so that it will fiow from the interior thevat I0 will flow downwardly through pipe I I to the exterior and therebyremove the foreign matter from the outside of the fine mesh screen. Thisoperation is effected by closing the valves 28 and and opening thevalves I4, 88, 9| and 98 after which the liquid will fiow from the vatI0 through pipe II, pump I2, pipe 24, pipes 89, 87 and 88 to theinterior of the filter grids 49 and 58 and into the upper compartment28. Only a small amount of reverse flow is necessary or can be efiectedbecause the upper compartment 20 will soon become filled; however, whenthe pressure becomes excessive within the upper compartment, suitablerelease Valve H0 can be opened to allow air as well as excess liquid toescape. The substance which is removed by this reverse flow settles ontop of partition 32, after which the scrapers 35 are oscillated to causethe filled following removal of sludge.

same to move downwardly into the lower compartment 3| through the slots33.

The release valve I I is positioned in the'sidewall of the tank 21instead of in the cap 62 as heretofore has been the case. By sopositioning the valve, the solvent or cleansing fluid is not allowed torise to the junction point of the tank and the cap. Since a gasket 62amade of rubber or other material, is usually positioned between the capand the tank to perfect the seal, it is desirable to prevent anysolution from contacting it that might damage it. Many solutions used inapparatus of this type are injurious to rubber compounds. If it isdesired to backwash only one of the filter grids, the valves 90 or SImay be closed, depending upon which grid is to be backwashed. Forexample, when only filter grid 49 is to be backwashed, the valve 90 isopened and the valve BI is closed; whereas if only filter grid 50 is tobe backwashed, the valve 90 is closed and the valve 9| is opened.

By referring to Figures 2 and 4, it will be seen that where the pipe 25enters the lower compartment 21 that another pipe I I2 is provided. Thispipe extends diametrically across the lower portion of the compartment26 at a slight distance above the bottom 32. The'extreme left hand endof this pipe has a cap I I3 secured thereon and cut in the opposed sidesof the pipe I I2 are slots H5 and IIBQ The slot I I5 is out only in thenear side of the pipe as shown in Figure 2 and the slot H6 is out onlyin the far side of the pipe. These slots provide an outlet through whichthe fluid leaves the pipe. Due to the position of the slots, a clockwisewhirling motion of the fluid will be produced in the lower portion ofthe tank.

A suitable drain valve II! is provided in the lower portion of thecompartment 21. Drain valve Ill is important because it allows cleanliquid to be withdrawn from the filter whenever it is necessary to drainthe filter down for the purpose of opening the sludge door I20. Afterthe grids have been either scraped down or backwashed, handle AI isrotated and the spent filter cake is disposed of in the sludge chamber.The valve II! can be opened and the relatively clear fluid can bewithdrawn from the active filter compartment and temporarily stored in atank or even in the washing machine; and the fluid is usually in goodcondition for recirculating through the filter after the filter has beenre- Other filters do not have a partition 32 separating the activefilter compartment 26 from the sludge chamber 32 and the withdrawal offluid from the filter is I quite a serious problem because the muckrises up whenever the fluid is withdrawn with any rapidity at all, withthe result that the withdrawn fluid is relatively dirty and must besettled or treated before it is in condition to be used again. Likewisedrain valves H8 and H9 are provided in the lower compartment 3|. Inorder to provide a suitable means for access to the lower compartment, aclean-out door I20 has been disposed over an opening or manhole I2Iwhich leads from the lower compartment to the exterior. The cover issecured over this opening by means of suitable bolts I22 and nuts I23.If desired, a suitable pressure gauge I25 may be provided for indicatingthe amount of pressure present in the casing 21. g

In the sludge compartment 3I a cartridge filter arrangement has beendevised for allowing the liquid to be discharged therethrough, leavingthe muck within the compartment in a practically dry condition. Thisfiltering arrangement is broadly designated by reference characters I 25and comprises a pipe I21 having perforations I2'Ia therein. A cap I28 isfastened over one end of the pipe by means of a bolt I29, said boltpenetrating the central portion of the pipe and having its other endthreadably secured to the interior of clean out door I20. It is,therefore, seen that the bolt I29 also secured the pipe I26 to theclean-out door. The pipe I28 is surrounded by a coarse mesh screen I 30which in turn is covered by a fine mesh Monel screen I3I. A valve I32 isopened to allow the filtered liquid to escape. When it is desired todischarge the liquid from the muck in compartment 3| the cleaning vatand the pump are out of operation, but all valves leading to the tank2'! are closed with the exception of valves H8 and I32. Then compressedair is forced into the compartment 3I through valve H8. This air willforce the liquid from the muck through the filter cartridge and outthrough valve I32, leaving the muck in a practically dry or moltenstate. If the pump should be started with all of the discharge valvesclosed an excessive pressure would ordinarily be built up within thepump, tank and piping system. An excessive pressure would probablydamage the filter grids as well as other parts of the system. In orderto prevent this excessive pressure, a by-pass pipe I36 has beeninstalled between the inlet pipe II and discharge pipe 24, said by-passpipe having a spring loaded discharge relief valve I31 therein, whichwill allow any excess pressure on the discharge side of the pump to passback to the intake side.

In actual filtering, the filter is first prepared for use by agitating aporous filter powder in the vat or washer for a period of approximately10 minutes to cause proper suspension of the filter powder in the fluid.The fluid is then circulated through the filter proper and the powderdeposits itself on the screen surfaces to form the porous coating.

Following this, loads of garments are placed in the vat or washer and aporous filter powder is also added. It is also common practice to add afullers earth or a chemical powder with the garments and agitate theload for at least 10 minutes after which circulation is turned on andthe filter powder acts as a carrier of the fullers earth or chemicalpowder and the Whole is added to the precoat originally deposited uponthe grids.

In the dry cleaning process, the most commonly used fluid has apetroleum base or it can be one of the synthetic solvents such as carbontetrachloride or the like. However, the filter should not be understoodas being restricted to the dry cleaning process alone.

Especial attention is called to the back washing feature'wherein thevertically disposed passageways I08 and I09 are provided as an integralpart of the sidewalls of the filter grids and having openings III!communicating with the space between the filter screens. Due to the sizeof these openings when back washing takes place, instead of the liquidall passing out around the bottom of the filter, it is approximatelyequally distributed throughout the height of the filter grid andtherefore all portions of the filter grid are back washed, that is thedeposited filter cake I is disposed off the exterior surface of thescreens. Attention is also called to the feature of the cartridge filterI26 disposed in the sludge compartment. It is attached-to the door I20so that it can be easily removed with the door I20 for the purpose ofbeing cleaned. When compressed air is forced into the casing 21, thefilter cake is deposited deeply and tightly into the meshes of thescreen I26 of the cartridge filter and by having the cartridge filtereasily removable rom the sludge chamber, the cleaning of the same isfacilitated.

In the drawings and specification there has been set forth a preferredembodiment of the invention, and although specific terms are employedthey are used in a generic and descriptive sense only, and not forpurposes of limitation, the scope of the invention being set forth inthe appended claims.

I claim:

1. In a pressure filter of the class described, a container, ahorizontally disposed partition dividing the container into upper andlower compartments, a plurality of concentrically disposed circularfilter members disposed within the upper compartment, an input pipedisposed below the filters and having oppositely directed slots in itssides and being disposed on opposed sides of the center of the containerfor imparting swirling motion to the incoming fiuid, a plurality ofoutput conduits leading to the exterior or the container, and havingseats disposed within the upper compartment, each filter having innerand outer filtering surfaces and a member having a channel communicatingwith the interior portion of the filter and having seats adapted to seatin the seats on the ends of the output conduits, a cylindrical baiilemember disposed in the center of the upper compartment for directing thefluid against the filters, the horizontally disposed partition having aslot therein, a scraper member normally closing said slot, meansextending to the exterior of the casing for imparting rotary motion tosaid scraper to establish communication between the upper and lowercompartments and to scrape the deposited filter cake from the uppersurface of the partition and deposit the same in the lower compartmentthrough said slot.

2. In a pressure filter of the class described for filtering fluids andemploying a filter cake or powder, a container, a horizontally disposedpartition dividing the container into upper and lower compartments, aplurality of concentrically disposed filter members disposed within theupper compartment, an input pipe disposed below the filters and havingoppositely directed slots therein on opposed sides of the center of thecontainer for imparting a swirling motion to the incoming fiuid, aplurality of output pipes leading to the exterior of the container andhaving seats disposed within the upper compartment, the filters havinginner and outer filtering surfaces, a connection communicating with theinterior portion of the filter and having seats adapted to seat in theseats on the ends of the output pipes, a bafiie member disposed in thecenter of the upper compartment for directing the fluid against thefilters, the horizontally disposed partition having a slot therein, ascraper member normally closing said slot, means extending to theinterior of the casing for imparting rotary motion to said scraper toestablish communication between the upper and lower compartments and toscrape the deposited filter cake from the upper surface of the partitionand deposit the same in the lower compartment through said slot, afilter member disposed within the lower compartment and means forestablishing communication between the exterior of the lower compartmentand the interior of the last-named filter for withdrawing fluid from thelower compartment through said filter.

3. In a fluid pressure filter of the class described and employing afilter cake or powder, a container, a horizontally disposed partitiondividing the container into upper and lower compartments, a plurality ofconcentrically disposed filter members disposed within the uppercompartment, means disposed below the filters and having oppositelydirected openings therein on opposed sides of the center of thecontainer for imparting a swirling motion to the incoming fluid, aplurality of output pipes leading to the exterior of the container andhaving seats disposed within the compartment, the filters having innerand outer filtering surfaces and a piped connection for each filtercommunicating with the interior portion of the filter and having a seatadapted to seat in one of the seats on the output pipes, abaflie memberdisposed in the center of the upper compartment for directing the fiuidagainst the filters, the horizontally disposed partition having a slottherein, a scraper member normally closing said slot, means extending tothe exterior of the casing for imparting rotary motion to said scrapermember to establish communication between the upper and lowercompartments and to scrape the deposited filter cake from the uppersurface of the partition and deposit the same in the lower compartmentthrough said slot, a filter member disposed within the lowercompartment, means for establishing communication between the exteriorof the compartment and the interior of the last-named filter forwithdrawing liquid from the lower compartment through said filter, thelower compartment-having an opening in its sidewall, a cover removablysecured to said opening, the last named filter being secured to saidcover whereby upon removal of the cover the last-named filter may beremoved from the lower compartment and access gained to the lowercompartment for removing filter cake deposited therein,

4. In a pressure filter for removing impurities from liquid solvents andthe like and adapted to use a filter powder which is deposited in cakeform on the filter during the filtering operation, a casing having upperand lower compartments, a plurality of concentrically disposed filtersin the upper compartment, each of said filters comprising a pair ofspaced fine mesh screens adapted to stop the filter powder and to allowthe solvent to pass therethrough, each of said filters having avertically disposed pipe communicating with the space defined by the twofine mesh screens, each pipe being divided by a vertically extendingpartition and having openings communicating with the space between thescreens, means for forcing the fluid to be cleaned into the lowerportion of the upper compartment, means for withdrawing the fluid fromthe lower end of said pipes which communicate with the space defined byfine mesh screens, a baffle member substantially filling the centralportion of the upper compartment for directing the fluid to be cleanedagainst the said screens, a partition separating the upper and lowercompartments and having a slot therein, a scraper blade normally closingsaid slot and means for imparting movement to the scraper blade to opensaid slot and to scrape deposited cake of filter powder from the uppersurface of said partition and deposit it in the lower compartment, thepartition in said pipes in said filters permitting the foreign matter tobe washed from the space defined by the fine mesh'scree'nsby injecting afiuid'under pressure on one side of said partition in said pipes toforce the fluid through the space defined by the fine mesh screens andback through the other side of the pipe.

5. In a pressure filter for removing impurities from dry cleaningsolvents wherein a filter cake is employed in the filtering operation, acasing, a horizontally extending partition dividing the easing intoupper and lower compartments, a radially disposed slot in saidpartition, a scraper member normally closing said slot, means forrotating the scraper member to remove deposited filter cake from theupper surface of said partition and to deposit the same through saidslot into the lower compartment, a plurality of concentrically disposedfilters disposed in spaced relation to each other in the uppercompartment,

each filter comprising a pair of spaced fine mesh screens, a supportingmember disposed between the two screens, each filter having a pair ofvertically disposed passageways adjacent each other, and having spacedopenings establishing communication with the space between the fine meshscreens, means for forcing the solvent into the upper compartment belowthe lower ends of said filters, hollow members penetrating the casing,seats establishing communication between the space between the fine meshscreens and the hollow members, means for withdrawing the fiuidoutwardly through the hollow members, means for removably securing thefilters in position, a cylindrical baflle member disposed concentricallyof the filters and inside of the innermost filter, the adjacentpassageways in said filters permitting foreign matter to be washed frombetween the fine mesh screens by injecting a liquid under pressure intoone passageway to force it around the entire filter and out through theother passageway.

6. A filter apparatus for removing impurities from solvents in drycleaning establishments comprising a casing, a plurality ofconcentrically disposed filters disposed within said casing, a bafilemember disposed inside the smaller filter and concentrically of bothfilters, means for forcing the solvent into the casing below the loweredge of the filters, means for withdrawing the solvent from the interiorof the filters, each of said filters having a pair of verticallydisposed passageways adjacent each other integral with its side wallsand communicating with the interior of the filters, whereby foreignmatter can be removed from the interior of the filters by forcing theliquid under pressure into one passageway to cause the liquid to fillthe filter and to, return through said other passageway. V

7. A filter apparatus for removing impurities from dry cleaning solventscomprising a casing, a horizontally disposed partition dividing thecasing into upper and lower compartments, a plurality of concentricfilters disposed in the upper compartment, means for forcing the solventinto the upper compartment below the lower edge of the filters,-a bafilemember disposed in vertical position around the center of the uppercompartment, means for withdrawing the solvent from the interior of thefilters and passing it outside of the casing, said partition having aslot therein, a scraper member normally closing said slot and means forimparting rotary motion to said scraper to open said slot and to depositfilter cake, which has accumulated on the partition, through said slotand into the lower compartment, a foraminous filter disposed in thelower compartment, apiped connection between the exterior of the casingand the interior of the last-named filter, whereby solvent can bewithdrawn from the lower compartment through said last-named filter, andmeans for removing said last named filter from the lower compartment forcleaning the same and gaining access to the lower compartment forremoving filter cake therefrom.

8. In a pressure filter employing a filter powper or cake, for removalof impurities from dry cleaning solvents and the like, a casing having acompartment in which a plurality of concentrically disposed cylindricalfilters are arranged, a cylindrical baflle member disposed within thespace defined by the innermost of said plurality of filters, means forforcing the solvent below the lower edges of said filters, means forcreating a suction within the filters and withdrawing liquid from thecompartment through the filters andto the exterior of the compartment,each of said filters comprising cylindrical outer and inner finemeshscreens, a support disposed between the fine mesh screens, eachfilter having a pair of vertically disposed passageways therein disposedadjacent each other andcommunicat ing with the space between the finemesh screens and also communicating withthe means for passing the liquidto the exterior of the compartment, the pair of passageways permittingforeign matter which may pass through said fine mesh screens to beremoved from between the screens by removing them from the compartmentand forcing theliquid into one passageway through the entire spacebetween the fine mesh screens and out through the other passageway. v

9. A cylindrical filter comprising inner and outer spaced screens, rigidannular members closing the ends of the screens, a member having a pairof adjacent passageways forming a part of the sidewalls of the filterand being slotted to establish communication with the space defined bythe fine mesh screens, whereby foreign matter can be expelled from thespace between the fine mesh screens by injecting a fiuicl into onepassageway to fill the space between the screens and to force the fluidand foreign matter out through the other passageway. V

10. A filtering apparatus comprising a filter chamber with a pluralityof filter grid structures therein of cylindrical formation andhaving'upright grid surfaces, means discharging fluid to be filteredinto-said chamber at a point belowthe filters, said means havingoppositely directed openings for imparting a horizontal rotaryswirlingmovement to the fiuid and a baflle member for directing thefluid in its upward travel over the grid surfaces, means for withdrawingfluid from the interior of the filters and passing it to the outside ofthe chamber, means to support the the filter chamber, said bottom havinga discharge opening from the filter chamber into the sludge receivingchamber, and means normally closing the opening and being operable toopen theopening and to scrape sludge from the bottom of the filterchamber and depositing it through said opening into the sludge receivingchamber. ""11; A filtering apparatus comprising a ifilter space in thechamber to permit a deposit of the heavy solid matter precipitated fromthe fluid and from the grid means to accumulate in the settling space, acylindrical bafile member disposed centrally of the filter chamber andbeing of approximately the same height as the concentric cylindricalfilters, a sludge receiving chamber beneath the bottom of the filterchamber, said bottom having a slot opening from the filter chamber intothe sludge chamber, a scraper means normally closing said slot, meansoperable from the exterior of the filter to move said closure andscraper means from over the slot to scrape sludge-from said bottom anddeposit it through said slot into the sludge receiving chamber, meansfor withdrawing the filtered fluid from the interior of said filteringgrid means and returningit to the outside of the filter, said meanscomprising a pair of separated and adjacent passageways communicatingwith the interior of the filtering grid means, said pair'of passagewayspermitting foreign matter to be washed from the interior of thefiltering grid means by removing the filtering grid means from thefilter and forcing a liquid-into one of said passageways and out throughthe other of said passageways.

12. In a filter for solvents used in dry cleaning apparatus andemploying a filter powder, a casing, a partition dividing the interiorof the casing into upper and lower compartments, a filter disposed inthe upper compartment, an opening in said partition, means normallyclosing the opening and being movable over the partition to scrapefilter powder from the partition and into said opening to allow it tofall into the lower compartment, means for circulating the solventthrough the filter in the upper compartment, a hollow filter memberdisposed in the lower compartment, means for withdrawing the solventfrom the lower compartment through the lastnamed filter.

13. In a filter for solvents used in dry cleaning apparatus andemploying a filter powder, a casing, a partition dividing the interiorof the casing into upper and lower compartments, a filter disposed inthe upper compartment, an opening in said partition, means normallyclosing the opening and being movable over the partition to scrapefilter powder from the partition and into said opening to allow it tofall into the lower compartment, means for circulating the solventthrough the filter in the upper compartment, means for withdrawing thesolvent from the lower compartment through the lastnamed filter, anopening in the wall of the lower compartment, a plate for closing theopening, and means for securing the last-named filter to the said plateso that when the plate is removed from over the opening the filter willbe also removed from the lower compartment.

14. In a pressure filter of the class described, for filtering fluidsand employing a filter cake or powder, a container, a horizontallydisposed partition dividing the container into upper and lowercompartments, a plurality of concentrically disposed circular filtermembers disposed within the upper compartment, an input pipe disposedbelow the filters and having oppositely directed slots in its sides andbeing disposed on opposed sides of the center of the container forimparting swirling motion to the incoming fluid, a plurality of outputconduits leading to the exterior of the container and having seatsdisposed within the 7 upper compartment, each filter having inner andouter filtering surfaces and a member having a channel communicatingwith the interior portion of the filter and having seats adapted to seatin the seats on the ends of the output conduits, a cylindrical bafiiemember disposed in the center of the upper compartment for directing thefluid against the filters, the horizontally disposed partition having aslot therein, a scraper member normally closing said slot, meansextending to the exterior of the casing for imparting rotary motion tosaid scraper to establish communication between the upper and lowercompartments and to scrape the deposited filter cake from the uppersurface of the partition and deposit the same in the lower compartmentthrough said slot, and means for reversing the flow in the input andoutput pipes for washing deposited filter cake from the exterior surfaceof the inner and outer filtering surfaces.

15. In a pressure filter of the class described for filtering fiuid andemploying a filter cake of powder, a container, a horizontally disposedpartition dividing the container into upper and lower compartments, aplurality of concentrically disposed filter members disposed within theupper compaitment, an input pipe disposed below the filters and havingoppositely directed slots therein on opposed sides of the center of thecontainer for imparting a swirling motion to the incoming fluid, aplurality of output pipes leading to the exterior of the container andhaving seats disposed within the upper compartment, the filters havinginner and outer filtering surfaces, a connection communicating with theinterior portion of the filter and having seats adapted to seat in theseats on the ends of the output pipes, a baflle member disposed in thecenter of the upper compartment for directing the fluid against thefilters, the horizontally disposed partition having a slot therein, ascraper member normally closing said slot, means extending to theexterior of the casing for imparting rotary motion to said scraper toestablish communication between the upper and lower compartments and toscrape the deposited filter cake from the upper surface of the partitionand deposit the same in the lower compartment through said slot, afilter member disposed within the lower compartment, means forestablishing communication between the exterior of the lower compartmentand the interior of the last-named filter for withdrawing fluid from thelower compartment through said filter, and means for reversing the flowin the input and output pipes for washing deposited filter cake from theexterior surface of the inner and outer filtering surfaces.

16. In a pressure filter for removing impurities from liquid solventsand the like and adapted to use a filter powder which is deposited incake form on the filter during the filtering operation, a casing havingupper and lower compartments, a plurality of concentrically disposedfilters in the upper compartment, each of said filters comprising a pairof spaced fine mesh screens adapted to stop the filter powder and toallow the solvent to pass therethrough, each of said filters having avertically disposed pipe communicating with the space defined by the twofine mesh screens, each pipe being divided by a vertically stantiallyfilling the central portion of the upper compartment for directing thefluid to be cleaned against said screens, a partition separating theupper and lower compartments and having a slot therein, a scraper bladenormally closing said slot and means for imparting movement to thescraper blade to open said slot and to scrape de: posited cake of filterpowder from the upper surface of said partition and deposit it in thelower compartment, the partition in said pipes in said filterspermitting foreign matter to be washed from the space defined by thefine mesh screens by injecting a fluid under pressure on one side ofsaid partition in said pipes to force the fluid through the spacedefined by the fine mesh screens and back through the other side of thepipe, and means for reversing the direction of fiow of the fluid intoand out of the upper compartment for removing the filter cake depositedon the exterior surface of the fine mesh screens.

17. In a pressure filter for removing impurities from dry cleaningsolvents wherein a filter cake is employed in the filtering operation, acasing,

a horizontally extending partition dividing the.

easing into upper and lower compartments, a radially disposed slot insaid partition, a scraper member normally closing said slot, means forrotating the scraper member to remove deposited filter cake from theupper surface of said partition and to deposit the same through saidslot into the lower compartment, a plurality of concentrically disposedfilters disposed in spaced relation to each other in the uppercompartment, each filter comprising a pair of spaced fine mesh screens,a supporting member disposed between the two screens, each filterhaving'a pair of vertically disposed passageways adjacent each other,and having spaced openings establishing communication with the spacebetween the fine mesh screens, means for forcing the solvent into theupper compartment below the lower ends of said filters, hollow memberspenetrating the casing, seats establishing communication between thespace between the fine mesh screens and the hollow members, means forwithdrawing the fluid outwardly through the hollow members, means forremovably securing the filters in position, a cylindrical bafile memberdisposed concentrically of the filters and inside of the innermostfilter, the adjacent passageways in said filters permitting foreignmatter to be washed from between the fine mesh screens by injecting aliquid under pressure into one passageway to force it around the entirefilter and out through the other passageway, and means for reversing theflow of the solvent through the filters for-washing deposited filtercake from the exterior surfaces of the fine mesh screens.

18. In a filter apparatus for removing impurities from solvents in drycleaning establishments comprising a casing, a, plurality ofconcentrically disposed filters disposed within the said casing, abafile member disposed inside the smaller filter and concentrically ofboth filters, means for forcing the solvent into the casing below thelower edge of the filters, means for withdrawing the solvent from theinterior of the filters, each of said filters having a pair ofvertically disposed passageways adjacent each other integral with itssidewalls and communicating with the interior of the filters, wherebyforeign matter can be removed from the interior of the filters byforcing the liquid under pressure into one passageway to cause theliquid to fill the filter and to return through said other passageway,and means for reversing the flow of the solvents through the filters.

19. In a pressure filter for removing impurities from dry cleaningsolvents and employing a filter powder or cake, a casing, a cylindricalfilter grid disposed in said casing and having its lon-.

gitudinal aXis disposed in a vertical plane, said filter comprisingspaced inner and outer filtering screens joined at their upper and lowerends, said filter grid having a vertically disposed portion providedwith a passageway on each side thereof in communication with theexterior of the filter grid, each passageway having openingsestablishing communication between the passageways and the space betweenthe filtering screens, means for forcing the solvent into the casingbelow the filter, means communicating with said passageways forwithdrawing the solvent from the space between the filtering screens,means for reversing the direction of flow through said filtering screensto remove deposited filter cake from the exterior surfaces of thefiltering screens, said adjacent passageways, when the filter grid isremoved from the casing, permitting a liquid to be forced into one ofthe passageways and withdrawn from the other passageway to remove theforeign matter from the space between the walls of the filter grid.

20. A filter comprising spaced screens, means closing the space betweenthe outer edges of the screens, a vertically disposed pipe filling thespace between the screens where the pipe is located, said pipe having avertically disposed partition providing a passageway on each sidethereof, opposed sides of each passageway having a communication withthe space between screens, and each passageway terminating in a commonseat at one end of the screens whereby both passageways may serve toadmit liquid into the space between the screens or to withdraw liquidfrom the space between the screens, said passageways also permittingliquid to be forced inwardly through one passageway and outwardlythrough the other passageway to remove foreign matter from the interiorproximate surfaces of thte screens and the space therebetween.

21. A filter comprising spaced screens, means closing the space betweenthe outer edges of the screens, a longitudinally disposed partitionmember disposed between the screens and filling the space between thescreens where the partition member is located, said partition memberhaving a passageway on each side thereof, in communication with thespace between the screens, whereby foreign matter can be expelled fromthe space between the screens by injecting a fluid into one passagewayto fill the space between the screens and to force the fiuid and foreignmatter out through the other passageway.

BLAINE KELLEY.

